This invention relates to an extrusion die for forming thin-walled honeycomb structures from extrudable materials such as glass, glass-ceramics, ceramics, plastics, metals, cermets and other materials, especially those in particulate form, which are capable of being extruded through relatively small holes or channels whose length is several times their diameter or transverse dimension and which, after extrusion, will substantially immediately become rigid enough to retain the extruded shape, i.e., a honeycomb configuration.
Thin-walled honeycomb structures display utility in a variety of technologies. For example, thin-walled honeycomb structures fashioned from ceramic materials exhibit utility as catalytic converters in the exhaust system of internal combustion engines. They also exhibit utility as radiators, catalyst carriers, filters, and heat exchangers.
The prior art is aware of a number of extrusion die constructions for forming thin-walled honeycomb structures, such as shown in U.S. Pat. Nos. 3,790,654 issued to Bagley, 3,824,196 issued to Benbow and 4,354,820 issued to Yamamoto.
Additionally, U.S. Pat. No. 4,465,454 issued to Duerr et al discloses a die for extruding thin-walled honeycomb structures, wherein the slots on the outer outlet face of the face plate are arranged so as to produce longitudinal channels which are square in transverse cross-section. Further, the inlet surface of the face plate is provided with a plurality of feed reservoirs which are aligned with the feed holes in the body plate. The feed reservoirs each communicate with a plurality of secondary (face plate) feed holes, the latter each discharging to a respective (face plate) discharge slot segment.